The invention of application Ser. No. 07/770,567, filed concurrently herewith, is a pipe coupling/connection provided with a seal that simulates the seal one would obtain by shrink-fitting a cylindrical box seal onto a mating cylindrical pin seal, preferably modified by increasing the load pressure at the proximal end of the pin sealing surface by designing the coupling to provide, as the coupling is being assembled, sealing area interference at least about as soon as and preferably before there is any interference between the load threads of the pin and box in the vicinity of the sealing area. Preferably the load threads of the coupling have negatively inclined load flank faces.